In the fields of physical therapy, sports medicine, hand surgery, home and gymnasium relaxation therapy and other related fields there is a demonstrable need for analeptic devices and environments for the exercise, temperature control and stimulation of injured or otherwise physically compromised body extremities. This is particularly true in connection with therapy directed to the hands. It is well known that in the treatment of and recuperation from manual injury, post-surgical recovery or disease, it is extremely important that the hand be provided with restorative and invigorating exercise in an environment that will promote recovery. Many different medical conditions require such exercise and stimulation, including: manual injury, surgical intervention, chronic joint disease and inflammation, carpal tunnel syndrome, vascular disorders, neurological disorders, and exercise fatigue to name a few. Optimal recovery requires the correct level of exercise and stimulation, which is usually, but not necessarily, carried out with medical supervision. Often, this exercise and stimulation is easier to achieve with the help of supplemental equipment. However, a survey of existing equipment and environments shows that each have specific drawbacks and inadequacies.
For example, in one kind of therapy, the hand or other extremity to be treated is immersed in liquid wax, removed and then re-immersed a number of times in order to build up a layer of hot material which resists passive movement. This therapy is known to have brought some benefits to some patients. However, the wax is frequently too hot for comfort, especially in light of the inherent tenderness of the region to be treated. In addition, wax also tends to provide too much resistance to movement, resulting in a non-therapeutic experience. Another drawback of wax is that visual monitoring of movement is generally impaired due to the translucency or opacity of the wax. And finally, for some patients the removal of the hardened wax at the end of the therapy session may be uncomfortable, painful, or even dangerous.
Another technique intended for the treatment and rehabilitation of specific tendon, joint or bone injuries, or to ameliorate the effects of surgery, involves the surface attachment of elastic elements between the tips of injured fingers and the forearm. This technique, known as "dynamic splinting" (described in detail in "Hand Splinting" by Judith C. Wilton, WB Saunders and Company, 1997) may be used, for example, to assist in returning injured fingers to a grasping position after they have been extended under exercise. The elastic elements provide gentle resistance to the extensor (hand-opening) muscles without requiring the active contraction of the flexor (grasping) muscles. However, practice has shown that it is difficult to devise equipment that provides the same kind of gentle resistance in the opposite direction, ie, a technique for applying resistance to the flexor (grasping) muscles of the hand which then returns the fingers to an extended position, without the active use of the extensor (hand-opening) muscles. In other words, experience has shown that this kind of therapy works well in one direction but not the other. In addition, this kind of therapeutic technique is not well suited for use in providing equal resistance to each individual digit regardless of it's direction of movement.
In a similar vein, there are a number of products on the market which provide for the unidirectional exercise of the hand, usually in a grasping action. Squeezable rubber balls, certain kinds of putty, and bead-filled pouches may all be purchased as therapeutic hand devices. However, each of these devices suffer the same limitation of exercising the grasping muscles much more than the extending muscles.
In addition to therapy focused on the exercise of specific muscles in open air, therapy techniques involving the direct immersion of a body extremity in water or in a viscous liquid are also sometimes practiced for their therapeutic effects. Such therapies have the advantage of allowing temperature control, in addition to providing therapeutic resistance. However, one drawback of such therapies is that the water or other liquid used is often not viscous enough to provide optimal, or even useful, resistance to movement. An additional drawback is that in this kind of therapy the liquid employed needs to come into direct contact with the skin of the user, which is frequently undesirable, inconvenient, and hinders portability. One solution to the direct contact problem is to provide flexible, webbed rubber gloves as a barrier between the user and the liquid. Unfortunately, in practice these kinds of gloves do not allow easy and universal movement of delicate or damaged digits, and only provide the fluid resistance of the water in which they are used.
Therefore, as can be seen from the above discussion, a first significant limitation of the prior art is that physical therapy, relaxation and recreational therapy equipment is often cumbersome and impractical for use in the hospital bed, the work-place, during travel, or in domestic settings.
Another limitation of the prior art is that very often it is desirable to practice different kinds of physical therapy in sequence or even simultaneously. For example, a manual exercise might then be followed by an electro-stimulation therapy, which may then be followed by a hot or cold immersion therapy. As is easily understood, the sequential and/or simultaneous implementation of all three techniques is not generally possible, despite the knowledge that in some instances, such enhanced therapeutic techniques can provide enhanced beneficial results.
Turning, next, to the enclosed liquid component of the instant invention, while the above described needs and techniques are directed to the provision of precisely controlled therapeutic resistance, it is also known that it is highly beneficial to provide padding or some other shock absorbing mechanism in conjunction with the application of therapy or exercise. By way of example, it is known that in order to protect against impact during exercise or movement various visco-elastic pads and orthotics may be used to provide a soft surface against which to press a bodily extremity. However, while such padding may utilize elements found in common with the invention, these elements are not used in an immersion manner, and do not provide the desired therapeutic results.
For example, while it is known that liquid-filled flexible products exist which are used in various applications such as cold-compress packs for various parts of the body, soft shoe insoles and orthotics, or other pads; as noted, these devices are used as external application devices rather than an integral part of an immersion chamber, and do not permit (nor even offer as desirable) a way to allow the free and separate movement of the digits within the liquid, for example.
In addition, while it is also known that in the field of prosthetics there are also products employing liquid or gel filled flexible capsules and sockets to provide a more comfortable protective surface for damaged or surgically altered extremities, these products are prosthetic interfaces and do not provide a liquid environment in which the digits or extremities may move universally through the liquid, and against the fluid resistance of that liquid.
Therefore, regardless of the merits and advantages of the existing therapies and devices mentioned above, none of them achieves all of the purposes of the physical therapy immersion device of the present invention.
Accordingly it has been determined that a need exists for devices which provide many types of gentle exercise and stimulation for body extremities such as the hands, which are easy to use, may be reused, provide a comfortable, safe, washable, portable, stimulating and restorative environment for physical therapy or relaxation, and which can permit the simultaneous use of multiple therapeutic agents (exercise, thermal stimulation, light therapy, ultrasound therapy, electro-stimulation, and clear visibility).